Jerzy Drozd Legend VI fretless - I've never played another fretless that sounded so organic and expressive; almost like a human singing voice. Ebow-like sustain. Playability, ergos, and workmanship are state-of-the-art. (There's a used one up for sale at [Invalid or Expired Link Removed] - very rare! The complex original Legend design was recently discontinued in favor of a much simpler version.) I reviewed mine here:
http://www.talkbass.com/reviews/showproduct.php/product/1257/cat/all
Old neck-through F-Basses - I'm not sure why, but George's pricey and comparatively soft and polite-sounding new bolt-ons just don't compare to his late 80's/early 90's neck-throughs for raw growl, presence and punch.
Pre-Gibson Tobias Basic/Classic/Signature - Warm, smokey, woody, organic, mid-complex and unique sounding. Top workmanship and great ergos. Amazing bang for the buck, even at today's "vintage" prices. A little heavy, but very well-balanced. MTD USAs are damn fine basses too, but nothing cuts like the old pre-Gibs. The Gibson copies I've played weren't even close.
Bee Basses - Excellent build quality, ergos, and balance. Heavyweight tone in a lightweight instrument that practically plays itself. Fred's innovative, modern, outside-the-box design aesthetic is a real breath of fresh air amid the tired legion of me-too Fender-clones.
Ken Lawrence C-Brase II fretless VI - Finally had a chance to play one. Wish I could afford it

. A work of musical art by a true master luthier. This one is at [Invalid or Expired Link Removed]